Projector and operation control method

Abstract

A projector includes a light source, a light modulation device configured to modulate a light output from the light source, a projection optical device configured to project the light modulated by the light modulation device, a casing containing at least a part of the light modulation device and having an interior filled with a cooling liquid, a circulating device configured to circulate the cooling liquid at least to a light exiting side of a modulation part in the light modulation device, and a control device configured to control an operation of the circulating device. The control device changes an operation level of the circulating device.

What is claimed is: 
     
       1. A projector comprising:
 a light source; 
 a light modulation device configured to modulate a light emitted from the light source; 
 a projection optical device configured to project the light modulated by the light modulation device; 
 a casing containing at least a part of the light modulation device and having an interior filled with a cooling liquid; 
 a circulating device configured to circulate the cooling liquid at least to a light exiting side of a modulation part in the light modulation device; and 
 a control device configured to control an operation of the circulating device, wherein 
 the control device changes an operation level of the circulating device, 
 the control device alternately executes
 a first control of controlling the operation of the circulating device at a first operation level and 
 a second control of controlling the operation of the circulating device at a second operation level, and 
 
 a velocity of the cooling liquid circulating on the light exiting side of the modulation part when the circulating device is controlled at the second operation level is higher than a velocity of the cooling liquid circulating on the light exiting side of the modulation part when the circulating device is controlled at the first operation level. 
 
     
     
       2. The projector according to  claim 1 ,
 wherein the control device executes the first control during a predetermined period after a start of lighting of the light source. 
 
     
     
       3. The projector according to  claim 2 ,
 wherein the control device stops the operation of the circulating device in the first control executed during the predetermined period. 
 
     
     
       4. The projector according to  claim 2 ,
 wherein the control device changes a length of the predetermined period based on a gradation of an image according to image information input to the light modulation device. 
 
     
     
       5. A projector comprising:
 a light source; 
 a light modulation device configured to modulate a light emitted from the light source; 
 a projection optical device configured to project the light modulated by the light modulation device; 
 a casing containing at least a part of the light modulation device and having an interior filled with a cooling liquid; 
 a circulating device configured to circulate the cooling liquid at least to a light exiting side of a modulation part in the light modulation device; and 
 a control device configured to control an operation of the circulating device, wherein 
 the control device changes an operation level of the circulating device, and 
 the control device changes the operation level of the circulating device based on an elapsed time after the start of lighting of the light source. 
 
     
     
       6. The projector according to  claim 5 ,
 wherein the control device changes the operation level based on both the elapsed time and a gradation of an image according to image information input to the light modulation device. 
 
     
     
       7. The projector according to  claim 1 , further comprising
 a detection device configured to detect a temperature of the cooling liquid, 
 wherein the control device changes the operation level based on the temperature of the cooling liquid detected by the detection device. 
 
     
     
       8. A projector comprising:
 a light source; 
 a light modulation device configured to modulate a light emitted from the light source; 
 a projection optical device configured to project the light modulated by the light modulation device; 
 a casing containing at least a part of the light modulation device and having an interior filled with a cooling liquid; 
 a circulating device configured to circulate the cooling liquid at least to a light exiting side of a modulation part in the light modulation device; and 
 a control device configured to control an operation of the circulating device, wherein 
 the control device changes an operation level of the circulating device, and 
 the control device changes the operation level so that a temperature of the cooling liquid falls within a predetermined temperature range. 
 
     
     
       9. An operation control method of a projector including a light source, a light modulation device configured to modulate a light emitted from the light source, a casing containing at least a part of the light modulation device and having an interior filled with a cooling liquid, and a circulating device configured to circulate the cooling liquid at least to a light exiting side of a modulation part in the light modulation device, the method comprising
 changing an operation level of the circulating device so that a temperature of the cooling liquid falls within a predetermined temperature range.